This invention relates to a display method and apparatus for navigation system for displaying information involved in guiding a driver of a vehicle, and more particularly, to a display method and apparatus for navigation system for displaying various kinds of screens and controlling the operation of the navigation system with use of a limited number of control keys.
A vehicle navigation system performs vehicle travel guidance enabling a driver to easily drive the vehicle to a selected destination. Such a navigation system detects the position of the vehicle, reads out map data pertaining to an area at the vehicle current position from a data storage medium, for example, a CD-ROM (compact disk read-only memory) or a DVD (digital videodisc), and displays a map image on a monitor (display) screen while superposing a mark representing the current location of the vehicle on a predetermined portion of the map image.
The vehicle position is determined by a self-contained navigation sensors (e.g. a distance traveled sensor and a bearing sensor) mounted in the vehicle or by a global positioning system (GPS) including a satellite (satellite navigation). The satellite navigation enables absolute position detection and higher position accuracy than the self-contained navigation sensors. However, the satellite navigation involves problem of position detection failure in a tunnel or a building where the satellite radio signals are obstructed. Therefore, recent navigation systems utilize both self-contained navigation and satellite navigation to achieve improved performances.
As the present position of the vehicle changes with the travel of the vehicle, the vehicle current position mark in the map image on the screen is changed accordingly. Alternatively, the map is scrolled while the vehicle current position mark stays at a predetermined position, for example, at the center of the image. In either methods, the navigation system enables the driver to recognize the map information of the area at the vehicle position at a glance.
When a destination is not set, such a navigation system functions as a locator map which indicates the current location of the vehicle on the map image. When the destination is set, the navigation system starts a route guidance function for setting a guided route from the starting point to the destination. Typically, the route guidance function performs an intersection guidance process in which a monitor screen displays an enlarged intersection diagram and the direction in which the vehicle is to travel while displaying the guide route on a map. When a starting point and a destination are input, a CPU in the navigation system automatically determines a most suitable guided route and successively stores nodes (expressed in longitude and latitude) constituting the guided route in a memory.
During actual traveling, the node series stored in the memory is searched for a portion of the guided route to be displayed in a map display area of the monitor screen, and the portion of the guided route is highlighted so as to be discriminable from other routes. When the vehicle is within a predetermined distance of an intersection it is approaching, an intersection guidance diagram (an enlarged or highlighted intersection diagram with an arrow indicating the direction in which the vehicle is to turn at the intersection) is displayed to inform a driver of the desired one of roads or directions selectable at the intersection.
FIG. 1A shows an example of locator map display containing a vehicle current position mark VCP on a map image 21. Typically, a navigation system highlights the street on which the vehicle is running in the map image 21 and shows a name of the street such as xe2x80x9cW 190TH STxe2x80x9d in an information box 23 on the display screen. Other information such as a north pointer NP, a map scale and a current time may also be illustrated on the display screen. In this manner, the locator map screen shows the current position of the vehicle on the map image, however, it does not perform the route guidance function because the destination is not set in the navigation system.
FIG. 1B shows an example of route guidance display which performs the route guidance function. The route guidance display is activated after specifying the destination of travel. In addition to the map image 21 similar to the locator map of FIG. 1A, this example further shows an arrow indicating the direction (left) in which the vehicle is to turn at the intersection in a guidance information box 22 at the top of the screen. The guidance information box 22 also shows a name of the street xe2x80x9cPRAIRIE AVExe2x80x9d which intersects with the current street xe2x80x9cW 190TH STxe2x80x9d and a distance to the intersection. Thus, the navigation system indicates that the vehicle should make a left turn at the intersection with xe2x80x9cPRAIRIE AVExe2x80x9d. Typically, the current street xe2x80x9cW 190TH STxe2x80x9d and the left side of the street xe2x80x9cPRAIRIE AVExe2x80x9d will be highlighted in the map image 21.
Further, such route guidance is accompanied by spoken instructions. If the direction of travel in the next intersection is left, the navigation system gives spoken guidance such as xe2x80x9cturn left at the next intersectionxe2x80x9d. In this example, an information box 24 at the bottom of the display screen includes information regarding the remaining distance to the final destination and an estimated time to reach the final destination.
In order to be guided by the route guidance mode such as shown in FIG. 1B, a destination must be specified in the navigation system so that the system can find one or more routes to get to the destination. FIGS. 2A-2F show examples of display shown on the screen during the operation of inputting the destination.
By operating a menu key, a main menu 25 such as shown in FIG. 2A is displayed on the navigation system and a menu item xe2x80x9cDestinationxe2x80x9d is selected from the main menu. This allows the navigation system to display a xe2x80x9cEnter Destination byxe2x80x9d menu 27 as shown in FIG. 2B for specifying an input method for selecting the destination. The xe2x80x9cEnter Destination byxe2x80x9d menu 27 lists various methods for selecting the destination including xe2x80x9cAddressxe2x80x9d for specifying the city and address of the destination, xe2x80x9cIntersectionxe2x80x9d for specifying the names of two streets which intersect with one another, and xe2x80x9cPoint of Interestxe2x80x9d for selecting the programmed destination based on the category or telephone number. Other methods in the xe2x80x9cEnter Destination byxe2x80x9d menu 27 include xe2x80x9cRecent Routexe2x80x9d for specifying the destination based on the recent destinations (history) saved in the navigation system, xe2x80x9cAddress Bookxe2x80x9d for selecting the address of the destination out of the list of addresses stored in the system, and xe2x80x9cMap Cursorxe2x80x9d for specifying the destination by pointing a cursor to the destination on the map.
When selecting the xe2x80x9cPoint of Interestxe2x80x9d in FIG. 2B, the navigation system displays a xe2x80x9cCategory Listxe2x80x9d menu 28 such as shown in FIG. 2C. The xe2x80x9cCategory Listxe2x80x9d menu 28 contains various different categories of destination such as xe2x80x9cBankxe2x80x9d, xe2x80x9cRestaurantxe2x80x9d, xe2x80x9cHotelxe2x80x9d, xe2x80x9cShoppingxe2x80x9d and others. Supposing the category xe2x80x9cShoppingxe2x80x9d is selected, the navigation system displays a xe2x80x9cName Listxe2x80x9d such as shown in FIGS. 2D and 2E. The xe2x80x9cName Listxe2x80x9d shows names of shops and shopping malls sorted by, for example, distance from the vehicle. In an address information box 31 on the display, the address and phone number of the highlighted name in the list 33 will be displayed. The address information box 31 may also show the distance to the highlighted shop. Typically, the navigation system stores several tens or hundreds of names of shops within predetermined distances and displays several shops per page of display screen, and a user may scroll the display screen to see other names of shops in the name list 36 such as shown in FIG. 2E.
When the desired destination is not prestored in the navigation system, a user can input the destination by selecting, for example, the xe2x80x9cAddressxe2x80x9d method or xe2x80x9cIntersectionxe2x80x9d method in the xe2x80x9cEnter Destination byxe2x80x9d menu 27 of FIG. 2B. Then, the navigation system displays an xe2x80x9cEnter Street Namexe2x80x9d shown in FIG. 2F for inputting the city and address in an address input box 37 by means of a key board 38 displayed on the display screen.
After inputting the destination, the navigation system determines a route to the destination based on, for example, by finding the shortest way to reach the destination. In the navigation system, the foregoing process of specifying the destination can be done either when the vehicle is running or stationary. While driving, a driver may want to change the destination or to set a new destination after reaching the original destination.
The operation of the navigation system, such as inputting the destination, requires the driver to press several keys of the navigation system. The driver has to look at the information on the display screen such as shown in FIGS. 2A-2C, or scroll the display such as shown in FIGS. 2D and 2E, or even input the destination through the key board such as shown in FIG. 2F. Thus, the navigation system may distract the driver""s attention from safe driving. Therefore, for maintaining safe driving, it is necessary to simplify the operation of the navigation system by simplifying the key arrangement in the navigation system such as reducing the number and kind of keys.
It is, therefore, an object of the present invention to provide a display method and apparatus for vehicle navigation system which enables a driver to operate the vehicle navigation system with use of a limited number of keys without inversely affecting the functions of the navigation system.
It is another object of the present invention to provide a display method and apparatus for vehicle navigation system which enables a driver to easily and efficiently control the operation of navigation system.
It is a further object of the present invention to provide a display method and apparatus for vehicle navigation system which is capable of changing between a map screen and a zoom screen and adjusting a map scale or a zoom scale of a map image without using dedicated control keys.
In the present invention, the navigation system is designed to achieve an easy and efficient operation by a driver for displaying information or changing displayed images with use of a substantially simplified set of control keys. In the navigation system, an enter key functions not only to set and select a menu but also to switch between a map screen and a map zoom screen. Cursor keys function not only to scroll a map image in the map screen but also to adjust a zoom scale of the map image in the map zoom screen.
One aspect of the present invention is a display method of a navigation system such as a vehicle navigation system. The display method is comprised of the steps of displaying a map screen in which a map image is scrolled by operation of cursor keys, changing the map screen to a map zoom screen by operating an enter key in which a zoom scale of the map image is changed by operation of the cursor keys and a cursor marker is displayed at a predetermined position on the screen, and returning to the map screen from the map zoom screen by pressing the enter key. A zoom scale bar is displayed on the map zoom screen t show a degree of zoom scale and the zoom scale bar is dismissed in the map screen.
The map screen includes a locator map screen in which a vehicle current position is shown on the map image and a map scroll screen in which the cursor marker stays on a predetermined position on the screen and the map image is scrolled in up, down, right and left directions by the operation of the cursor keys. A map scale of the map screen is determined by the zoom scale in the map zoom screen. For example, the map scale in the map screen is increased from the zoom scale in the map zoom screen when the zoom scale is smaller than a predetermined level and when the enter key is pressed in the zoom screen before operating the cursor key.
The zoom screen includes a balloon image which shows a message associated with an area specified by the cursor marker when the zoom scale of the map image is smaller than a predetermined scale. Further, the map screen and the map zoom screen include POI (point of interest) icons each indicating POI locations by a predetermined icon. The POI icons are displayed when a map scale in the map screen or the zoom scale in the map zoom screen is larger than a predetermined scale.
The zoom scale bar in the map zoom screen includes a zoom slider which moves in a right or left direction on the zoom scale bar in response to the operation of the cursor key and changes an icon thereon depending on the position on the zoom scale bar wherein the icon on the zoom slider indicates a type of next screen that will be displayed when pressing the enter key.
The message accompanied by the balloon image indicates availability of a name list corresponding to POI (point of interest) icons in the area specified by cursor marker in a name list screen that will be displayed when pressing the enter key. The name list screen displays a list of names and addresses of the POI and a position of the cursor marker, and wherein a destination is selected through the name list screen and a route to the selected destination is determined by the navigation system.
Preferably, a map scale of the map screen is determined by the zoom scale in the map zoom screen when the enter key is pressed in the zoom screen before operating the cursor key. For example, the map scale in the map screen is increased to a high range map scale from the zoom scale in the map zoom screen when the zoom scale is smaller than a predetermined high threshold level but is larger than a predetermined middle threshold level, and the map scale in the map screen is increased to a middle range map scale from the zoom scale in the map zoom screen when the zoom scale is smaller than the predetermined middle threshold level.
In another aspect of the present invention, a display method of a vehicle navigation system is comprised of the steps of displaying a locator map screen in which a vehicle current position is shown on a map image, changing the locator map screen to a map scroll screen by operating cursor keys in which a map image is scrolled in up, down, right and left directions in response to the operation of the cursor keys while a cursor marker is displayed at a predetermined position on the map scroll screen, changing either from the locator map screen or the map scroll screen to a map zoom screen by pressing an enter key in which a zoom scale of the map image is changed by operation of the cursor keys and the cursor marker is displayed at a predetermined position on the map zoom screen, and selecting the zoom scale by pressing the enter key after adjusting the zoom scale by operating the cursor keys in the map zoom screen, thereby returning to the locator map screen with the selected zoom scale or moving to a name list screen in which a list of names of POI (point of interest) specified by the cursor marker or an address of a location specified by the cursor marker is displayed. A zoom scale bar is displayed on the map zoom screen to show a degree of zoom scale, and the zoom scale bar is dismissed in the map screen.
A further aspect of the present invention is a display apparatus of a vehicle navigation system. The display apparatus includes means for displaying a locator map screen in which a vehicle current position is shown on a map image, means for changing the locator map screen to a map scroll screen by operating cursor keys in which a map image is scrolled in response to the operation of the cursor keys while a cursor marker is displayed at a predetermined position on the map scroll screen, means for displaying a map zoom screen by pressing an enter key in which a zoom scale of the map image is changed by operation of the cursor keys and the cursor marker is displayed at a predetermined position on the map zoom screen, and means for returning to the map screen from the map zoom screen by pressing the enter key, wherein a zoom scale bar is displayed on the map zoom screen to show a degree of zoom scale and the zoom scale bar is dismissed in the locator map screen or map scroll screen.
According to the present invention, the display method and apparatus for vehicle navigation system enables the driver to operate the navigation system with use of a reduced number of control keys without adversely affecting the safe driving of the vehicle. Since the number and type of control keys are reduced, the driver is able to operate the navigation system easily and quickly. Further, since the arrangement of control keys is simplified, the driver can driver the car safely without being distracted by operating the navigation system. Since the control key arrangement in the navigation system is simplified, the space required for the panel of the navigation system can be reduced.